1. Technical Field
The disclosure relates to an image processing apparatus, an image processing method, and a computer-readable recording medium for identifying abnormalities in a microstructure on a surface of an examination target in an image which is obtained by capturing the inside of a lumen of a living body.
2. Related Art
For image processing performed on an image which is obtained by capturing the inside of a lumen of a living body by a medical observation apparatus such as an endoscope or a capsule endoscope (hereinafter, also referred to as an intraluminal image or simply referred to as an image), for example, Japanese Patent Application Laid-open No. 2005-192880 discloses a technique for detecting, from an image, abnormal parts determined based on the microstructure of a mucosal surface or the form of a blood vessel course. More specifically, in an intraluminal image, an image composed of a G (green) component that includes a relatively large amount of information about a mucosal microstructure and a blood vessel image is extracted. Thereafter, feature data where a pixel value pattern of a mucosal surface is quantified (see, for example, Japanese Patent No. 2918162 and Japanese Patent Application Laid-open No. 2002-165757) is computed. Then, using the feature data and a linear discriminant function which is created in advance based on intraluminal images with normal and abnormal findings, it is discriminated whether a subject (mucous membrane) in the intraluminal image is normal or abnormal. Note that Japanese Patent No. 2918162 discloses shape feature data (an area, a groove width, a perimeter length, the degree of circularity, a branch point, an edge point, a branching rate, etc.) of a region extracted by binarizing an image of a specific spatial frequency component. In addition, Japanese Patent Application Laid-open No. 2002-165757 discloses feature data obtained based on spatial frequency analysis using a Gabor filter, etc.